Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Monthly payment
$1,580.17
Remaining balance
$234,027
Interest paid so far
$78,838
Principal paid so far
$15,973
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter loan amount ($).
- 2Enter interest rate (%).
- 3Enter loan term (years).
- 4Enter show balance after (years) (years).
- 5Read your monthly payment on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Break down a fixed-rate loan into total interest paid and balance after a given number of payments.
Worked example
Using the values the calculator loads with:
Inputs
- Loan amount: 250000 $
- Interest rate: 6.5 %
- Loan term: 30 years
- Show balance after (years): 5 years
Results
- Monthly payment: $1,580.17
- Remaining balance: $234,027.44
- Interest paid so far: $78,837.65
- Principal paid so far: $15,972.56
What each field means
Inputs
- Loan amount ($)
- The loan amount used in the calculation, measured in $. Starts at 250000 $ so you have a working example on load.
- Interest rate (%)
- The interest rate used in the calculation, measured in %. Starts at 6.5 % so you have a working example on load.
- Loan term (years)
- The loan term used in the calculation, measured in years. Starts at 30 years so you have a working example on load. Accepted range: 1–50 years.
- Show balance after (years) (years)
- The show balance after (years) used in the calculation, measured in years. Starts at 5 years so you have a working example on load.
Results
- Monthly payment
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Remaining balance
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Interest paid so far
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Principal paid so far
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the amortization calculator work?
Break down a fixed-rate loan into total interest paid and balance after a given number of payments.
What do I need to enter?
4 values: loan amount, interest rate, loan term, and show balance after (years). Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the monthly payment result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Amortization Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/amortization
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/amortization" target="_blank" rel="noopener">Amortization Calculator — RevenueLab</a> (2026).</p>
Source: [Amortization Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/amortization) (2026).